<!DOCTYPE html>
<html>
<head>

<script>

function boom()
{
  document.execCommand("inserthtml", false, "ABC ");
  document.execCommand("delete", false, null);
  document.execCommand("inserthtml", false, "<style>");
}

</script>
</head>

<body onload="setTimeout(boom, 0);" contenteditable="true"></body>
</html>
